textproduct: Rapid City

KEY MESSAGES

- Light snow across northwestern SD, northern Black Hills today - Gusty winds this afternoon, stronger winds Wednesday, both of which may cause local blowing snow where snow is present - Brief bout of arctic air by Friday, but strength and duration tenuous

DISCUSSION

(Today Through Monday) Issued at 208 AM MST Tue Jan 20 2026

09z surface analysis had frontal boundary from central MT into the NE panhandle with low pressure along it over central MT. Few radar returns aloft under mid-clouds streaming into the CWA ahead of the next shortwave noted over central AB/SK per water vapour loop. 100kt jet streak scooting it along. Effects of active north/northwest flow aloft and associated clippers remain the main forecast concern.

Today, shortwave races southeast allowing MT low to deepen slightly as it moves through CWA along frontal boundary. Main lift/moisture northeast of boundary where stripe of modest isentropic lift noted, nudged along by modest mid-level QG-forcing bubble. Expect a band of light snow (50% chance 0.1" QPF) across northwestern SD and then some upslope-enhancement (Froude>1, 0-2km RH ~90% from 20/18z-21/03z) for the Black Hills as trailing cold front shifts south. Perhaps a couple of inches of snow for the northern Black Hills. Other impact will be 2-4mb/3hr pressure rises behind cold front that will tap into 25-40kt lowest 2km northwest flow. Decent setup for Wind Advisory from K2WX-KRAP (40-70% chance >45mph gusts), so have hoisted. Some blowing snow may occur when snow is present with the higher winds, but WSSI isn't terribly excited about the prospect per minor impacts painted. Temperatures will be near guidance.

Tonight/Wednesday, stronger shortwave careens southeast out of Canada into the upper Midwest. It will drag a fast-moving cold front into the CWA early Wednesday with 3-6mb/3hr pressures rises behind it. Lowest 0-2km depicts 30-50kt winds with modest cold air advection/subsidence resulting in the potential for High Winds (40-70% chance >55mph gusts) on the plains of western SD. Doesn't look like the higher winds will last too long per forecast Bufkit soundings. Moisture/forcing will be scant, so not expecting much new snow. Given colder temperatures and potential new snow from today, blowing snow may be more of an issue. Will keep messaging simple this morning (with a Wind Advisory out) and let later shifts hone potential headlines for tomorrow. Temperatures will be near guidance.

Thursday/Friday, arctic air will ooze into the northern Plains with ~1051mb high bubbling into the northern Plains. We'll be on the western edge of the coldest air, so confidence in strength of arctic air still in question. Right now, Friday looks to be the coldest with potential Cold Advisory (LREF chance <-25F apparent temperature 50%+ from K2WX-KICR) headlines. Real moisture is scant.

Looking toward the weekend, we'll continue to be on the edge of the coldest air with temperatures spreads 15-25F, but with mean temperatures increasing. Confidence in details remain low.

AVIATION

(For the 18Z TAFS Through 18Z Wednesday) Issued At 1041 AM MST Tue Jan 20 2026

A cold front is forecast to move through the region today and bring increasing winds from the northwest. In advance of the frontal passage, winds will be generally light in the 5 to 10 mph range. As the front passes the areas terminals, winds will increase quickly with gusts from 30-45kts expected. In addition to the frontal passage, low level wind shear will also be a concern overnight. Surface winds will remain gusty through the overnight and into Wednesday morning.

The front will also bring areas snow showers primarily over the Black Hills and northwestern SD. Where snow occurs MVFR to locally IFR visibilities are anticipated with MVFR to low end VFR ceilings.Flight conditions due to restrictions from snow and low ceilings will improve by tonight generally around 00Z.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Wind Advisory until 6 PM MST this evening for SDZ001-012-013-031- 041-072-073. WY...None.